I have a 500, and then bought an 88 with a long barrel for an extra bird gun. I find that the 88 has a very stiff action compared to the mossberg 500. I would spend the extra few bucks and get the mossberg combo ( long and short barrels). It may still come with the pistol grip as an extra.
the stock on the 88 doesnt come with the "eyes" to attach a sling, so you have to hold it all the time, and the polymer stock isnt as nicely finished as the mossbergs either.. it has rough edges to it.
the longer barrels will accept a choke ( mine came with one), but the short barrels smooth bore, so you can shoot slugs.